Democratic presidential candidate Hillary Clinton is preparing for high political drama on Thursday when she testifies before the House Select Committee probing the 2012 terrorist attacks that killed four Americans in Benghazi, Libya. Clinton was secretary of state at the time of the attacks and her testimony could have an impact on her White House hopes for 2016.

Republicans on the committee are expected to grill Clinton about the terror attacks that took four American lives, including U.S. Ambassador to Libya Chris Stevens, on September 11, 2012.

But Clinton has tried to put the focus on the committee by seizing on Republican comments that the Benghazi panel is targeting her politically. The Clinton campaign put out an ad that included a now-infamous clip of House Majority Leader Kevin McCarthy talking about the Benghazi probe in an interview with Fox News.

"Everybody thought Hillary Clinton was unbeatable, right?" he asked rhetorically. "But we put together a Benghazi special committee. What are her [poll] numbers today?"

Clinton also went on the offensive toward the committee during the recent Democratic presidential debate.

"This committee is basically an arm of the Republican National Committee," she said. "It is a partisan vehicle as admitted by the House Republican Majority Leader, Mr. McCarthy, to drive down my poll numbers – big surprise – and that is what they have attempted to do."

Benghazi, Libya

Republicans defend probe

The Republican committee chairman, Representative Trey Gowdy of South Carolina, acknowledged on CBS’ “Face the Nation” that some comments from his fellow Republicans have been a distraction.

"I have told my own Republican colleagues and friends: Shut up talking about things that you don’t know anything about," he said on the program, which aired Sunday. "And unless you’re on the committee, you have no idea what we’ve done, why we’ve done it and what new facts we have found."

House Speaker John Boehner insisted the congressional probe is about finding out the truth, not politics.

The "Benghazi committee is about what happened before, during and after a terrorist attack in Libya where four Americans died," Boehner said. "The American people deserve the truth about what happened, period."

FILE – The late U.S. Ambassador to Libya Chris Stevens, left, greets a Libyan man in this photo posted on the U.S. Embassy Tripoli Facebook page on Aug. 27, 2012.

Clinton opponents with the Stop Hillary PAC are running a controversial ad that include pictures of the four Americans killed in the attack, accompanied by a voiceover that asks: "Dear Hillary Clinton. I’d like to ask you why you ignored calls for help in Benghazi."

Democrats highlight politics

Democrats say, given the recent Republican comments, it is the Benghazi committee that is on trial.

"The question also becomes whether this is a taxpayer-funded effort to derail the candidacy of Hillary Clinton," said the committee’s top Democrat, Representative Elijah Cummings of Maryland.

White House spokesman Josh Earnest also said the Benghazi committee is under intense scrutiny. "Thus far, we haven’t seen them produce much, so I think the pressure will really be on them to, frankly, justify their own existence."

Clinton has been in this position before. She fended off Senate Republicans in 2013 in a heated exchange when she was asked what was behind the attacks on two U.S. sites – the diplomatic mission and a nearby CIA compound – in Benghazi.

"The fact is we had four dead Americans," she said then. "Was it because of a protest or was it because of guys out for a walk one night who decided they would go kill some Americans? What difference at this point does it make?"

FILE - A Libyan man walks in the damaged U.S. consulate after an attack the night of Sept. 11, 2012, in Benghazi, Libya.

Key campaign moment

Given Clinton’s presidential aspirations, the political stakes for her appearance are huge, said Republican strategist Ford O’Connell. "And I think the optics [appearance] of it could really be damaging to Hillary Clinton, regardless of what comes out of that hearing," he said.

But Clinton is used to controversy and remains politically formidable, countered analyst John Fortier of the Bipartisan Policy Center in Washington.

"I think it is hard for Hillary Clinton to change the big perception of her," he said. "She is very well known, but that has its pluses and minuses. She is going to have strong negatives. She has had them for a long time and there are plenty of people who know her and don’t like her. But she’s also got strong supporters."

Clinton got high marks for her debate performance and continues to lead challenger Bernie Sanders in national polls. But a major unknown looming over the Democratic race is whether Vice President Joe Biden will join the field and, so far, Biden isn’t saying.

Jim Malone has served as VOA’s National correspondent covering U.S. elections and politics since 1995. Prior to that he was a VOA congressional correspondent and served as VOA’s East Africa Correspondent from 1986 to 1990. Jim began his VOA career with the English to Africa Service in 1983.